This is true, for most people, the photos never technically leave your local area network. However most people don’t know how to properly secure their network, and even those that do know how easy it is to hack. It may not be online readily available for the world to see, but it is online enough that if someone wants it, they can get it…

Regarding the Eye-Fi Card, when you set it up to send photos just to your local computer, the pictures don’t leave your local wireless network (unless you specifically set up “relayed uploads”). This feature is available across all the Eye-Fi cards, not just the Eye-Fi Pro.